Media pick-up device of media dispenser

ABSTRACT

Disclosed is a media pickup device of a media dispenser which can use various kinds of media having different thickness by varying an overlap amount between a feeding roller and a separating roller. To this end, the device comprises: a feeding roller and a separating roller arranged with a predetermined interval for separating media discharged from a media cassette sheet by sheet and feeding; and a variable means for varying an overlap amount between the feeding roller and the separating roller according to thickness of media.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a media dispenser, and more particularly, to a media pick-up device of a media dispenser which can use various kinds of media of different thickness.

[0003] 2. Description of the Related Art

[0004]FIG. 1 is a construction view showing a media dispenser in accordance with the conventional art.

[0005] As shown in FIG. 1, the media dispenser according to the conventional art comprises: a base plate 6 in which a media cassette 2 for storing media and a reject box 4 for collecting inferior media are loaded; a media pickup unit 8 installed at the lower side of the base plate 6 for discharging the media stored in the media cassette 2 by separating sheet by sheet; a media feeding unit 10 for feeding the media discharged through the media pickup unit 8; a media discharging unit 12 for discharging the media fed by the media feeding unit 10 to outside; a driving means for generating driving force; a power transmitting means for transmitting the driving force generated at the driving means to each unit; and a media rejection means for separating and collecting abnormal media.

[0006] The base plate 6 has an interior loading space for loading the media cassette 2 at the front side, another interior loading space for loading the reject box 4 for loading inferior media at the upper side of the above interior loading space, and a door 16 at the front side of the two interior loading spaces.

[0007] A locking system 18 for preventing an arbitrary external access to the media cassette 2 and the reject box 4 is installed at the door 16. Also, a cushion member 20 abutted on the front surface of the media cassette 2 for buffering impact is installed on the inner surface of the door 16.

[0008] A power board 22 for using the power supplied from outside in overall components of the media dispenser directly is installed at the lower side of the position where the media cassette 2 of the base plate 6 is loaded.

[0009] It is desirable that the driving means is a driving motor 24 installed at one side of the base plate 6 for generating rotational force. A driving pulley 26 is installed in the driving motor 24.

[0010] The above power transmitting means transmits power generated in the driving motor 24 to each unit. A driving pulley 26 of the driving motor is connected to a driven pulley 30 by a driving belt 28 and power is transmitted to the driven pulley 30. A timing belt 32 is wound on the driven pulley 30, a lower connection pulley 34 for driving the media pickup unit 8 is wound at the lower end of the timing belt 32 and an eject pulley 36 for driving the media discharging unit 12 is wound at the upper end of the timing belt 32.

[0011] A plurality of tension pulleys 38 and 40 for maintaining tension of the timing belt 32 are installed at one side of the timing belt 32.

[0012] The lower connection pulley 34 transmits rotational force generated by the rotation of the timing belt 32 to the media pickup unit 8 and transmits the rotational force to the media feeding unit by being connected to the media feeding unit.

[0013] The media feeding unit 10 for guiding the media discharged through the media pickup unit 8 to the media discharging unit 12, comprises a first feeding belt 74 wound between a first feeding roller 70 which is positioned on the identical shaft as the lower connection pulley 34 and a second feeding roller 72 positioned at the upper side; and a second feeding belt 76 positioned under the condition of being abutted to the first feeding belt 74, which is rotated to feed the media.

[0014] The first feeding belt 74 is wound between the first feeding roller 70 which is positioned on the identical shaft as the above lower connection pulley 34 and the second feeding roller 72, rotating by receiving rotational force from the above lower connection pulley 34 and a plurality of guide rollers 78 and 80 for guiding the media are installed at one side of the first feeding belt 74 rotatably.

[0015] The second feeding belt 76 positioned under the condition of being abutted to the outer surface of the first feeding belt 74 rotates in the same direction of the first feeding belt 74 and is wound between a third feeding roller 82 which is positioned at the lower side of the base plate 6 rotatably and a fourth feeding roller 84 positioned at the upper front end of the base plate 6.

[0016] A plurality of guide rollers 86 and 88 for guiding the second feeding belt 76 are positioned at one side of the second feeding belt 76.

[0017] Here, the fourth feeding roller 84 is positioned on the identical shaft as a gear 90 in gear with the eject pulley 36 on which the timing belt 32 is wound and receives the rotational force thus to drive the above second feeding belt 76.

[0018] In the above media feeding unit 10, when the driving motor 24 is driven, the timing belt 32 rotates and accordingly, the lower connection pulley 34 and the eject pulley 36 rotate. Then, the first feeding roller 70 positioned on the identical shaft as the lower connection pulley 34 rotates and has the first feeding belt 74 rotate. The fourth feeding roller 84 in gear with the eject pulley 36 rotates and has the second feeding belt 76 rotate.

[0019] Then, the media discharged through the above media pickup unit 8 pass through between the first feeding belt 74 and the second feeding belt 76 and are guided to the media discharging unit 12.

[0020] The media discharging unit 12 discharges the media fed from the media feeding unit 10 to the user and the media discharging unit 12 comprises a first discharging roller 98 which is positioned on the identical shaft as the eject pulley 36 and rotates; and a second discharging roller 100 connected to the first discharging roller 98 by a discharging belt 102. The discharging belt 102 under the condition of being abutted to the upper side of the second feeding belt 76 is rotated in the same direction and discharges the media to outside.

[0021] As shown in FIGS. 2 and 3, the media pickup unit 8 for discharging the media cassette by separating sheet by sheet, comprises: a pickup roller 42 positioned at the rear side of the media cassette 2 for discharging the media stored in the media cassette 2 to the lower direction by friction; a feeding roller 44 and a separating roller 46 positioned at the lower side of the pickup roller 42, for feeding the media discharged by the pickup roller 42 by separating the media sheet by sheet; and a guide member 48 for guiding the media fed through the feeding roller 44 and separating roller 46 to the upper direction.

[0022] The pickup roller 42 is positioned at the rear side of the media cassette 2 rotatably and a rubber unit 50 is formed on a certain part of the circumferential surface. Accordingly, the rubber unit 50 rubs with the media, discharges the media by separating and receives power in gear with the feeding roller 44.

[0023] Namely, a driving gear 60 and a driven gear 58 are installed on the rotation shafts 54 and 56 of the feeding roller and the pickup roller, and an idle gear 52 is in gear between the driving gear 60 and driven gear 58 thus to transmit the rotational force of the feeding roller 44 to the pickup roller 42.

[0024] Pulleys 110 and 112 are respectively fixed to the rotation shaft 56 of the feeding roller 44 and the rotation shaft 114 of the separating roller 46, and a connection belt 62 is wound between the pulleys 110 and 112 thus to be rotated in the same direction. Also, the feeding roller 44 and the separating roller 46 maintain a predetermined overlap thus to feed the media discharged through the pickup roller 42 by separating sheet by sheet. That is, several sheets of media are inputted as the feeding roller 44 rotates, and the several sheets of media inputted by the rotation of the feeding roller 44 are separated one sheet by one sheet by friction in accordance with that the separating roller 46 rotates in the same direction of the feeding roller 44.

[0025] Herein, in case that the overlap amount between the feeding roller 44 and the separating roller 46 is fixed as about 0.4 mm, media having thickness only of 0.1˜0.3 mm can be used.

[0026] A clutch 64 for controlling power transmitted from the lower connection pulley 34 to the feeding roller 44 is installed at the rotation shaft 54 of the feeding roller 44. That is, the clutch 64 is installed on the same shaft as the feeding roller 44 and connected in gear with the lower connection pulley 34 by a clutch gear 66, thereby transmitting or intercepting the power transmitted from the lower connection pulley 34 to the feeding roller 44.

[0027] Herein, the clutch 64 uses a solenoid method to transmit power in case power supply is applied and intercept power in case power supply is intercept. Contrarily, another solenoid method to intercept power in case power supply is applied and transmit power in case power supply is intercept can be used.

[0028] Such media pickup unit 8 transmits the rotational force of the lower connection pulley 34 to the feeding roller 44 when the clutch means 64 is on. Then the separating roller 46 wound on the feeding roller 44 by the connection belt 62 rotates, and the pickup roller 42 in gear with the feeding roller 44 rotates together. Then, as the pickup roller 42 rotates, the rubber unit 50 of the pickup roller 42 discharges the media downwardly by being rubbed with the media. The media discharged by the pickup roller 42 are separated passing through between the feeding roller 44 and the separating roller 46 and the separated media move upwardly along the guide member 48 and are guided to the media feeding unit 10.

[0029] When the clutch means 64 is turned off, power transmitted from the lower connection pulley 34 to the feeding roller 44 is intercept, thus to stop the media pickup operation.

[0030] According to on/off of the clutch means 64, the media pickup unit 8 performs pickup/pickup halting operation repeatedly.

[0031] However, in the media pickup device of the media dispenser, since the feeding roller 44 and the separating roller 46 are connected by the connection belt 62 and the overlap amount therebetween is fixed, only media having thickness proper to the overlap amount can be used. According to this, various kinds of media having various thickness can not be used.

SUMMARY OF THE INVENTION

[0032] Therefore, an object of the present invention is to provide a media pickup device of a media dispenser which can use various kinds of media having different thickness by installing a variable means at a separating roller and thus by varying an overlap amount between a feeding roller and the separating roller.

[0033] To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a media pickup device of a media dispenser comprising: a feeding roller and a separating roller arranged with a predetermined interval for separating media discharged from a media cassette sheet by sheet and feeding; and a variable means for varying an overlap amount between the feeding roller and the separating roller according to thickness of media.

[0034] At a rotation shaft of the separating roller of the media pickup device, installed is a one-way clutch which makes the separating roller maintain a static state in a direction where media pass and rotate in the opposite direction thereof

[0035] The variable means comprises: a supporting bracket for supporting both ends of the rotation shaft of the separating roller; a supporting shaft for rotatably supporting another side of the supporting bracket; and a torsion spring installed between the supporting shaft and the supporting bracket for providing a predetermined elastic force to push the separating roller to the feeding roller.

[0036] One side of the supporting bracket of the media pickup device is fixed to both ends of the rotation shaft of the separating roller, another side thereof is rotatably supported by being inserted to the supporting shaft, and a stopper for determining an initial overlap amount between the feeding roller and the separating roller is formed at one side thereof.

[0037] The torsion spring of the media pickup device is wound on the supporting shaft, and is formed as a coil spring of which one end is fixed on the supporting shaft and another end is fixed to the supporting bracket.

[0038] The media pickup device of the media dispenser according to the present invention comprises: a feeding roller and a separating roller arranged with a predetermined interval for separating media discharged from a media cassette sheet by sheet and feeding; a variable means for varying an overlap amount between the feeding roller and the separating roller according to thickness of media; and an adjusting unit for adjusting a maximum overlap amount between the feeding roller and the separating roller.

[0039] The variable means for varying the overlap amount comprises: a supporting bracket for supporting both ends of the rotation shaft of the separating roller; a supporting shaft for fixing another side of the supporting bracket and being rotatably supported by a base plate; and a tension spring connected to one side of the supporting shaft for pushing the separating roller to the feeding roller.

[0040] The tension spring is a coil spring connected between a connection bracket fixed to one side of the supporting shaft and a connection rod fixed to the base plate.

[0041] A stopper for determining an initial overlap amount between the feeding roller and the separating roller is contacted on the front surface of the connection frame, and an adjusting unit for adjusting a maximum overlap amount between the feeding roller and the separating roller is installed at the rear surface of the connection frame.

[0042] The adjusting unit of the media pickup device comprises: an adjusting bracket fixed to the base plate; and an adjusting bolt screw-engaged to the adjusting bracket and thus contacted to the rear surface of the connection frame for adjusting a maximum rotation amount of the supporting shaft.

[0043] The media pickup device of the media dispenser according to the present invention comprises: a feeding roller and a separating roller arranged with a predetermined interval for separating media discharged from a media cassette sheet by sheet and feeding; a tension spring for pushing the separating roller to the feeding roller in order to vary an overlap amount therebetween according to thickness of media; and a tension adjusting means for adjusting tension of the tension spring.

[0044] The tension adjusting means of the media pickup device is an adjusting bolt for adjusting tension of the spring by being inserted to a through hole formed at the connection frame and screw-engaged to a base plate.

[0045] The media dispenser according to the present invention comprises: a media pickup unit for discharging media stored in a media cassette by separating sheet by sheet; a media feeding unit for feeding the media discharged through the media pickup unit; and a media discharging unit for discharging the media fed through the media feeding unit to outside, in which the media pickup unit comprises: a feeding roller and a separating roller for separating media discharged from the media cassette sheet by sheet and feeding; and a variable means for varying an overlap amount between the feeding roller and the separating roller according to thickness of media by being connected to the separating roller.

[0046] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

[0048] In the drawings:

[0049]FIG. 1 is a construction view showing a media dispenser in accordance with the conventional art;

[0050]FIG. 2 is a perspective view showing a media pickup device in accordance with the conventional art;

[0051]FIG. 3 is a lateral view showing the media pickup device in accordance with the conventional art;

[0052]FIG. 4 is a lateral view showing a media pickup device according to the present invention;

[0053]FIG. 5 is a front view showing the media pickup device according to the present invention;

[0054]FIGS. 6 and 7 are views showing operational state of the media pickup device according to the present invention;

[0055]FIG. 8 is a lateral view showing the media pickup device according to a second embodiment of the present invention;

[0056]FIG. 9 is a frontal view of the media pickup device according to the second embodiment of the present invention;

[0057]FIG. 10 is a lateral view showing the media pickup device according to a third embodiment of the present invention; and

[0058]FIG. 11 is a front view of the media pickup device according to the third embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0059] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

[0060]FIG. 4 is a lateral view showing a media pickup device according to the present invention, and FIG. 5 is a front view showing the media pickup device according to the present invention.

[0061] Referring to FIG. 1, the media dispenser according to the present invention a base plate 6 in which a media cassette 2 for storing media and a reject box 4 for collecting inferior media are loaded; a media pickup unit 8 installed at the lower side of the base plate 6 for discharging the media stored in the media cassette 2 by separating sheet by sheet; a media feeding unit 10 for feeding the media discharged through the media pickup unit 8; a media discharging unit 12 for discharging the media fed by the media feeding unit 10 to outside; a driving means for generating driving force; a power transmitting means for transmitting the driving force generated at the driving means to each unit; and a media rejection means for separating and collecting abnormal media.

[0062] The media dispenser according to the present invention has the same construction and operation as that of the conventional art except the media pickup unit, thereby omitting its explanation.

[0063] As shown in FIGS. 4 and 5, the media pickup device according to one embodiment of the present invention comprises: a pickup roller 150 positioned at the rear side of the media cassette 2 for discharging the media stored in the media cassette 2 to the lower direction by friction; a feeding roller 154 and a separating roller 156 positioned at the lower side of the pickup roller 150, for feeding the media discharged by the pickup roller 150 by separating the media sheet by sheet; and a variable means installed at the separating roller 156 for varying an overlap amount between the feeding roller 154 and the separating roller 156.

[0064] The pickup roller 150 is positioned at the rear side of the media cassette 2 rotatably, and a rubber unit 152 is formed on a certain part of the circumferential surface. Accordingly, the rubber unit 152 rubs with the media, discharges the media stored in the media cassette 2 by separating.

[0065] The feeding roller 154 is positioned at the lower side of the pickup roller 150 rotatably, and a rotation shaft 158 of the feeding roller 154 is connected with the power transmitting means thus to rotate the feeding roller 154.

[0066] Also, a clutch 160 for controlling power transmitted from the power transmittance means to the feeding roller 154 is installed at the rotation shaft 158 of the feeding roller 154.

[0067] Herein, the clutch 160 uses a solenoid method to transmit power in case power supply is applied and intercept power in case power supply is intercept. Contrarily, another solenoid method to intercept power in case power supply is applied and transmit power in case power supply is intercept can be used.

[0068] The separating roller 156 is positioned to have a predetermined overlap amount with the feeding roller 154 and maintains a static state, so that media which passes through between the separating roller 156 and the feeding roller 154 can be separated sheet by sheet by friction.

[0069] That is, one way clutch 164 is respectively formed at both ends of a rotation shaft 162 of the separating roller 156. The one way clutch 164 makes the separating roller 156 maintain a static state in a direction where media pass thus to generate friction with the media, and makes the separating roller 156 rotate in the opposite direction thereof thus to prevent partial side wear from being generated at a friction surface of the separating roller 156.

[0070] The variable means comprises: a supporting bracket 166 for supporting both ends of the rotation shaft 162 of the separating roller 156; a supporting shaft 168 for rotatably supporting another side of the supporting bracket 166; and a torsion spring 170 installed between the supporting shaft 168 and the supporting bracket 166 for providing a predetermined elastic force to push the separating roller 156 to the feeding roller 154.

[0071] One side of the supporting bracket 166 of the media pickup device is wound and fixed to an outer circumference surface of the one way clutch 164 arranged both ends of the rotation shaft 162 of the separating roller 156, and another side thereof is rotatably supported by being inserted to the supporting shaft 168. Also, a stopper 172 is formed at one side thereof to prevent the supporting bracket 166 from being rotated more than a predetermined number of times by an elastic force of the torsion spring 170.

[0072] That is, the stopper 172 is prolonged from one side of the supporting bracket 166 and blocked by a blocking pin 174 fixed to the base plate 6. According to this, an initial overlap amount between the feeding roller 154 and the separating roller 156 is set.

[0073] At this time, the initial overlap amount between the feeding roller 154 and the separating roller 156 is set on the basis of a case that thickness of the media is minimum.

[0074] The supporting shat 168 rotatably supports the supporting bracket 166 under a state that both ends thereof are fixed to the base plate 6, respectively.

[0075] The torsion spring 170 formed of a coil spring is wound on the supporting shaft 168, and has one end fixed on the supporting shaft 168 and another end fixed to the supporting bracket 166. That is, the torsion spring 170 provides the elastic force to the supporting bracket 166 with one direction, thereby pushing the feeding roller to the separating roller.

[0076] The torsion spring 170 has a predetermined elastic force so as to vary the overlap amount between the separating roller and the feeding roller according to thickness of the media which pass through therebetween.

[0077] Operations of the media pickup device of the media dispenser according to one embodiment of the present invention will be explained.

[0078]FIGS. 6 and 7 are views showing operational state of the media pickup device according to the present invention.

[0079] If the driving means is operated, power is transmitted to the rotation shaft 158 of the feeding roller 154 through the clutch 160, thus the feeding roller is operated and the pickup roller 150 in gear with the feeding roller 154 is rotated.

[0080] When the pickup roller 150 is rotated, a media 180 stored in the media cassette 2 is rubbed with the rubber unit 152 of the pickup roller 150, discharges towards the lower direction, separated sheet by sheet by passing through between the feeding roller 154 and the separating roller 156, and guided by the media feeding unit 10, thereby being discharged to outside through the discharging unit 12.

[0081] At this time, the rotation shaft 162 of the separating roller 156 is supported by the one way clutch 164 and maintains a static state towards a direction where the media 180 is discharged thus to generate friction with the media 180 and to separate the media 180 sheet by sheet. Also, the rotation shaft 162 is rotated in the opposite direction thus to prevent partial side wear from being generated.

[0082] As shown in FIG. 6, when a thick media 182 passes through between the feeding roller 154 and the separating roller 156, the separating roller 156 overcomes an elastic force of the torsion spring 170 by a pushing force of the media 182 and then moves towards the lower side direction. According to this, an overlap amount between the feeding roller 154 and the separating roller 156 becomes less and thereby the thick media 182 can be easily separated.

[0083] Also, when a thicker media 184 is introduced, as shown in FIG. 7, the separating roller 156 more moves towards the lower side direction and thereby the overlap amount between the feeding roller 154 and the separating roller 156 becomes much less. At this time, the overlap amount is maintained by the elastic force of the torsion spring 170.

[0084]FIG. 8 is a lateral view showing the media pickup device according to a second embodiment of the present invention, and FIG. 9 is a frontal view of the media pickup device according to the second embodiment of the present invention.

[0085] The media pickup device according to the second embodiment of the present invention comprises: a feeding roller 154 and a separating roller 156 positioned at the lower side of the pickup roller 150 for separating the media discharged from the pickup roller 150 sheet by sheet and feeding; and a variable means installed at the separating roller 156 for varying an overlap amount between the feeding roller 154 and the separating roller 156 according to thickness of media.

[0086] The variable means comprises: a supporting bracket 190 for supporting both ends of the rotation shaft 162 of the separating roller 156; a supporting shaft 192 for fixing another side of the supporting bracket 190 and being rotatably supported by the base plate 6; and a tension spring 194 connected to one side of the supporting shaft 192 for providing a predetermined elastic force so that the supporting shaft 192 can be rotated in one direction.

[0087] The supporting bracket 190 has one end portion fixed on the supporting shaft 192 with a predetermined interval and the other end portion for supporting both ends of the rotation shaft 162 of the separating roller 156. A one way clutch 196 is installed at the rotation shaft 162 thus to rotate the separating roller 156 only in one direction.

[0088] A connection bracket 198 is fixed to one side of the supporting shaft 192 with a predetermined angle, and the tension spring 194 is connected between the connection bracket 198 and a connection rod 200 fixed to the base plate 6.

[0089] Also, a stopper 202 for setting an initial overlap amount between the feeding roller 154 and the separating roller 156 is contacted on the front surface of the connection bracket 198, and an adjusting unit for adjusting a maximum overlap amount between the feeding roller 154 and the separating roller 156 by controlling rotation amount of the supporting shaft 192 is positioned at the rear surface of the connection bracket 198.

[0090] The stopper 202 is fixed to the base plate 6 and contacted on the front surface of the connection bracket 198 and thereby prevents the supporting shaft 192 from being rotated more than a predetermined number of times by the elastic force of the tension spring 194. It is preferable that the initial overlap amount is set when thickness of the media is minimum.

[0091] The adjusting unit of the media pickup device comprises: an adjusting bracket 204 fixed to the base plate 6; and an adjusting bolt 206 screw-engaged to the adjusting bracket 204. The adjusting unit controls a distance between the connection bracket 198 and the adjusting bolt 206 by tightening or loosening the bolt 206, thereby controlling maximum rotation amount of the supporting shaft 192.

[0092] That is, if the adjusting bolt 206 is controlled, the maximum rotation amount of the supporting shaft 192 is set and thereby a maximum overlap amount between the feeding roller 154 and the separating roller 156 is determined.

[0093] Operations of the media pickup device according to the second embodiment of the present invention will be explained.

[0094] First, the distance between the adjusting bolt 206 and the connection bracket 198 is controlled by tightening or loosening the adjusting bolt 206, thereby determining maximum thickness of a media to be used.

[0095] Then, if the pickup roller 150 is rotated, the media 180 stored in the media cassette 2 is rubbed with the rubbing unit 152 of the pickup roller 150, discharged to the lower side direction, passes through between the feeding roller 154 and the separating roller 156, and thereby separated sheet by sheet.

[0096] At this time, in case that a thick media is used, the media is introduced between the feeding roller 154 and the separating roller 156 by the rotation of the feeding roller 154 and the separating roller 156 is separated from the feeding roller 154 by the introduction force of the media. According to this, the overlap amount between the separating roller 156 and the feeding roller 154 is controlled.

[0097] That is, the separating roller 156 maintains a predetermined overlap amount with the feeding roller 154 by having a predetermined elastic force by the torsion spring 194. Under this state, if a thick media is introduced, the separating roller 156 overcomes the elastic force of the torsion spring 194 and moves toward the lower side direction, thereby controlling the overlap amount with the feeding roller 154.

[0098]FIG. 10 is a lateral view showing the media pickup device according to a third embodiment of the present invention, and FIG. 11 is a front view of the media pickup device according to the third embodiment of the present invention.

[0099] The media pickup device according to the third embodiment of the present invention comprises: a feeding roller 154 and a separating roller 156 positioned at the lower side of the pickup roller 150 for separating the media discharged from the pickup roller 150 sheet by sheet and feeding; and a variable means installed at the separating roller 156 for varying an overlap amount between the feeding roller 154 and the separating roller 156 according to thickness of media.

[0100] The variable means comprises: a supporting bracket 220 for supporting both ends of the rotation shaft 162 of the separating roller 156; a supporting shaft 222 for fixing another side of the supporting bracket 220 and being rotatably supported by the base plate 6; a tension spring 224 connected to one side of the supporting shaft 222 for pushing the separating roller 156 to the feeding roller 154; and a tension adjusting means for adjusting tension of the tension spring 224.

[0101] A connection bracket 226 is fixed to one side of the supporting shaft 222, and a through hole 230 is formed at the connection bracket 226. An adjusting bolt 228 for adjusting tension of the tension spring 224 is inserted to the through hole 230, and screw-engaged to the base plate 6.

[0102] Herein, the through hole 230 has a size to maintain a predetermined distance with the adjusting bolt 228 in order to move right and left on the basis of the supporting shaft 222.

[0103] The tension spring 224 is installed between the connection bracket 226 and the adjusting bolt 228, and thus provides a predetermined elastic force to the connection bracket 226.

[0104] Like this, if the adjusting bolt 228 is tightened, the tension spring 224 is compressed and thus a tension of the spring becomes great, and vice versa.

[0105] A stopper 236 for adjusting an initial overlap amount between the feeding roller 154 and the separating roller 156 is positioned at the front surface of the connection bracket 226, and an adjusting unit 238 for adjusting a maximum overlap amount between the feeding roller 154 and the separating roller 156 by controlling rotation amount of the supporting shaft 192 is installed at the rear surface of the connection bracket 226.

[0106] Operations of the media pickup device according to the third embodiment will be explained.

[0107] Once the pickup roller 150 is rotated, the media stored in the media cassette 2 is rubbed with the pickup roller 150, discharged towards the lower side direction, passes through between the feeding roller 154 and the separating roller 156, and thereby separated sheet by sheet.

[0108] At this time, in case that a thick media is used, the media is introduced between the feeding roller 154 and the separating roller 156 by the rotation of the feeding roller 154, and the separating roller 156 overcomes the elastic force of the tension spring 224 by the introduction force of the media and is separated from the feeding roller 154. According to this, the overlap amount between the separating roller 156 and the feeding roller 154 is controlled.

[0109] At this time, if the adjusting bolt 228 is tightened or loosened, the tension spring 224 is compressed or relaxed and thereby intensity of force applied to the separating roller 156 is controlled.

[0110] That is, if the force applied to the separating roller 156 is great, the thick media has a difficulty in being discharged between the feeding roller 154 and the separating roller 156. Contrary to this, if the force applied to the separating roller 156 is less, friction force between the separating roller 156 and the media becomes weak and thereby the media can not be separated sheet by sheet. Therefore, the force applied to the separating roller 156 has to be maintained at the optimum state.

[0111] Accordingly, tension of the tension spring 224 is adjusted by tightening or loosening the adjusting bolt 228, and thereby the force applied to the separating roller 156 can be controlled as the optimum state.

[0112] The media pickup device of the media dispenser according to the present invention has the following effects.

[0113] The media pickup device can use various kinds of media having different thickness by installing the variable means which varies an overlap amount between the feeding roller 154 and the separating roller 156 at the separating roller 156.

[0114] As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalence of such metes and bounds are therefore intended to be embraced by the appended claims. 

What is claimed is:
 1. A media pickup device of a media dispenser comprising: a feeding roller and a separating roller arranged with a predetermined interval for separating media discharged from a media cassette sheet by sheet and feeding; and a variable means for varying an overlap amount between the feeding roller and the separating roller according to thickness of media.
 2. The device of claim 1, wherein a one-way clutch which makes the separating roller maintain a static state in a direction where media pass and rotate in the opposite direction thereof is installed at a rotation shaft of the separating roller.
 3. The device of claim 1, wherein the variable means comprises: a supporting bracket for supporting both ends of the rotation shaft of the separating roller; a supporting shaft for rotatably supporting another side of the supporting bracket; and a torsion spring installed between the supporting shaft and the supporting bracket for providing a predetermined elastic force to push the separating roller to the feeding roller.
 4. The device of claim 3, wherein one side of the supporting bracket is fixed to both ends of the rotation shaft of the separating roller, another side thereof is rotatably supported by being inserted to the supporting shaft, and a stopper for determining an initial overlap amount between the feeding roller and the separating roller is formed at one side thereof.
 5. The device of claim 4, wherein the stopper is prolonged from one side of the supporting bracket and blocked by a blocking pin fixed to a base plate.
 6. The device of claim 3, wherein an initial overlap amount between the feeding roller and the separating roller is set on the basis of a case that thickness of the media is minimum.
 7. The device of claim 3, wherein the torsion spring is wound on the supporting shaft, and is formed as a coil spring of which one end is fixed on the supporting shaft and another end is fixed to the supporting bracket.
 8. A media pickup device of a media dispenser comprising: a feeding roller and a separating roller arranged with a predetermined interval for separating media discharged from a media cassette sheet by sheet and feeding; a variable means for varying an overlap amount between the feeding roller and the separating roller according to thickness of media; and an adjusting unit for adjusting a maximum overlap amount between the feeding roller and the separating roller.
 9. The device of claim 8, wherein the variable means for varying the overlap amount comprises: a supporting bracket for supporting both ends of the rotation shaft of the separating roller; a supporting shaft for fixing another side of the supporting bracket and being rotatably supported by a base plate; and a tension spring connected to one side of the supporting shaft for pushing the separating roller to the feeding roller.
 10. The device of claim 9, wherein the tension spring is a coil spring connected between a connection bracket fixed to one side of the supporting shaft and a connection rod fixed to the base plate.
 11. The device of claim 10, wherein a stopper for determining an initial overlap amount between the feeding roller and the separating roller is contacted on a front surface of the connection frame, and an adjusting unit for adjusting a maximum overlap amount between the feeding roller and the separating roller is installed at a rear surface of the connection frame.
 12. The device of claim 11, wherein the adjusting unit comprises an adjusting bracket fixed to a base plate, and an adjusting bolt screw-engaged to the adjusting bracket and thus contacted to the rear surface of the connection frame for adjusting a maximum rotation amount of the supporting shaft.
 13. A media pickup device of a media dispenser comprising: a feeding roller and a separating roller arranged with a predetermined interval for separating media discharged from a media cassette sheet by sheet and feeding; a tension spring for pushing the separating roller to the feeding roller in order to vary an overlap amount therebetween according to thickness of media; and a tension adjusting means for adjusting tension of the tension spring.
 14. The device of claim 13, wherein one side of a supporting bracket supports both ends of the rotation shaft of the separating roller, another side thereof is fixed to a supporting shaft, the supporting shaft is rotatably supported by a base plate, a connection frame is fixed at one side of the supporting shaft, and the tension adjusting means supports the tension spring at one side of the connection frame.
 15. The device of claim 14, wherein the tension adjusting means is an adjusting bolt for adjusting tension of a spring by being inserted to a through hole formed at the connection frame and screw-engaged to the base plate.
 16. The device of claim 15, wherein the tension spring is a coil spring supported at a bolt head of the adjusting bolt and a lateral surface of the connection frame.
 17. The device of claim 14, wherein a stopper for determining an initial overlap amount between the feeding roller and the separating roller by limiting movement of the connection bracket is contacted on a front surface of the connection bracket, and an adjusting unit for adjusting a maximum overlap amount between the feeding roller and the separating roller by adjusting rotation amount of the rotation shaft is installed at a rear surface of the connection bracket.
 18. The device of claim 17, wherein the adjusting unit comprises an adjusting bracket fixed to a base plate, and an adjusting bolt screw-engaged to the adjusting bracket and thus contacted to a rear surface of the connection frame for adjusting a maximum rotation amount of the supporting shaft.
 19. A media dispenser comprising: a media pickup unit for discharging media stored in a media cassette by separating sheet by sheet; a media feeding unit for feeding the media discharged through the media pickup unit; and is a media discharging unit for discharging the media fed through the media feeding unit to outside, in which the media pickup unit comprises: a feeding roller and a separating roller for separating media discharged from the media cassette sheet by sheet and feeding; and a variable means for varying an overlap amount between the feeding roller and the separating roller according to thickness of media by being connected to the separating roller.
 20. The media dispenser of claim 19, wherein the variable means comprises: a supporting bracket for supporting both ends of the rotation shaft of the separating roller; a supporting shaft for rotatably supporting another side of the supporting bracket; and a torsion spring installed between the supporting shaft and the supporting bracket for providing a predetermined elastic force to push the separating roller to the feeding roller.
 21. The media dispenser of claim 20, wherein one side of the supporting bracket is fixed to both ends of the rotation shaft of the separating roller, another side thereof is rotatably supported by being inserted to the supporting shaft, and a stopper for determining an initial overlap amount between the feeding roller and the separating roller is formed at one side thereof. 